Method of preparing derivatives of polyarylene vinylene and method of preparing an electronic device including same

ABSTRACT

A technique is described for the preparation of polymers according to a process in which the starting compound of formula (I) is polymerized in the presence of a base in an organic solvent. No end chain controlling agents are required during the polymerisation to obtain soluble precursor polymers. The precursor polymer such obtained comprises structural units of the formula (II). In a next step, the precursor polymer (II) is subjected to a conversion reaction towards a soluble or insoluble conjugated polymer by thermal treatment. The arylene or heteroarylene polymer comprises structural units of the formula III. In this process the dithiocarbamate group acts as a leaving group and permits the formation of a precursor polymer of structural formula (II), which has an average molecular weight from 5000 to 1000000 Dalton and is soluble in common organic solvents. The precursor polymer with structural units of formula (II) is thermally converted to the conjugated polymer with structural formula (III).

CROSS-REFERENCE TO RELATED APPLICATION

This application is a division of U.S. application Ser. No. 10/971,784filed Oct. 21, 2004 now U.S. Pat. No. 7,259,228, which claims thebenefit under 35 U.S.C. § 119(a)-(d) of European application No.03447264.7 filed Oct. 22, 2003, the disclosures of which are herebyexpressly incorporated by reference in their entirety and are herebyexpressly made a portion of this application.

FIELD OF THE INVENTION

The present invention relates to a method for the preparation of solubleprecursor polymers of arylene and heteroarylene vinylene polymers andtheir conversion towards arylene and heteroarylene vinylene polymers,and to devices including the same.

BACKGROUND OF THE INVENTION

Conjugated polymers are of great interest for the development of opticaland electronic applications. The most investigated conjugated polymersare poly(thiophene) (PT) and poly(p-phenylene vinylene) (PPV). Alsopoly(2,5-thienylene vinylene) (PTV) has attracted great attentionbecause of its high electrical conductivity upon doping and its possibleapplication as a semiconductor in all-polymer field effect transistors.Additionally, PTV is a low band gap semiconductor polymer, which makesit a very interesting material for organic photovoltaic devices.

Several methods have been developed to synthesize PTV. In the earlydays, PTV was synthesised via the Wessling polymerisation method, whichis described in U.S. Pat. No. 3,401,152 by R. A. Wessling and R. G.Zimmerman and in J. Polym. Sci.: Polym. Symp. 1985, 72, 55 by R. A.Wessling. The polymerization reaction according to the Wessling methodis difficult, because the products tend to form a gel. Moreover, strongacids, which could be toxic, are required during the conversionreaction.

In 1987, Murase et al. and Yamada et al. reported the synthesis of PTVvia a precursor polymer with methoxy leaving groups (I. Murase, T.Ohnishi, T. Noguchi, M. Hirooka, Polym. Commun. 1987, 28, 229; S.Yamada, S. Tokito, T. Tsutsui, S. Saito, J. Chem. Soc., Chem. Commun.1987, 1448). This reaction is an acid catalysed conversion reaction,which is incompatible with device fabrication.

In 1990, Elsenbaumer et al. reported the synthesis and characterisationof PTV and some alkyl-substituted PTV's (R. L. Elsenbaumer, Mol. Cryst.Liq. Cryst 1990, 186, 211). These methods are far from ideal especiallyfor the PTV derivatives due to the relative high reactivity of themonomer and precursor polymer which complicates both monomer and polymersynthesis. The high reactivity is originated from the high electrondensity of the thiophene ring, which induces a very high instability ofthe starting monomer when this monomer is reached but generally with lowreproducibility and very low yields due to many side-reactions.

This is also the reason why problems occur by using the more recentprecursor methods like the sulfinyl route, developed by Vanderzande etal. in 1997 (A. J. J. M. Van Breemen, A. C. J. Issaris, M. M. de Kok, M.J. A. N. Van Der Borght, P. J. Adriaensens, J. M. J. V. Gelan, D. J. M.Vanderzande, Macromolecules 1999, 32, (18), 5728), the bis-xanthateroute developed by Son in 1995 and Burn et al. in 2001 and described in(US patent 1997/5,621,069; European patent EP 0 707 022 A2; S-C. Lo,L.-O. Palsson, M. Kilitziraki, P. L. Burn, I. D. W. Samuel, J. Mater.Chem. 2001, 11, 2228) and the bis-sulfide route developed by Herwig etal in 2003 (US patent 2003/0027963 A1).

To use PTV, other poly(arylene vinylene)s and poly(heteroarylenevinylene) derivatives in plastic electronics, an easy accessibleprecursor polymer that can be manufactured on a large scale isdesirable.

SUMMARY OF THE INVENTION

It is an object to provide a method for the synthesis of soluble orinsoluble conjugated polymers like arylene of heteroarylene vinylene,optionally in good yields, optionally with high molecular weight,optionally good quality, e.g. low defect level and optionally in largescale. It is a further aim to describe the use of these soluble orinsoluble conjugated polymers for organic solar cells, organictransistors and other kinds of electronic devices.

It is a further aim to describe a novel precursor polymer, to be used asintermediate compound in the synthesis of arylene of heteroarylenevinylene polymers.

In a first aspect, a method for the preparation of a precursor polymeris disclosed. The precursor polymer has the general formula

wherein Ar is an aromatic divalent group or a heteroaromatic divalentgroup, wherein R₀ is an organic group selected from the group consistingof an amine —NR₁R₂, a C₅-C₂₀ alkyloxy group, an aryloxy group, an alkylgroup, an aryl group, an alkylaryl group, an arylalkyl group, athioether group, an ester group, an acid carboxylic group, and aheterocyclic group, and wherein R₃ and R₄ are independently from eachother hydrogen or an organic group selected from the group consisting ofa C₁-C₂₀-alkyl group, a cyclic C₃-C₂₀-alkyl group, an aryl group, analkylaryl group, an arylalkyl group, a thioether group, an ester group,an acid carboxylic group and a heterocyclic group, and wherein n is thenumber of repeating units.

In a specific embodiment, the precursor polymer may have the formula asformula (II) wherein R₀ is an amine —NR₁R₂

and in which R₁ and R₂ are independently from each other an organicgroup selected from the group consisting of a C₁-C₂₀-alkyl group, acyclic C₃-C₂₀-alkyl group, an aryl group, an alkylaryl group, anarylalkyl group and a heterocyclic group, R₁ and R₂ may be linkedtogether to form a cycle. One typical example of such a precursorpolymer may be a precursor polymer wherein R₀=—NR₁R₂ and whereinR₁=R₂=Et:

In other specific examples of precursor polymers which may be used inembodiments, R₀ may be a phenyl group, a methyl group or a group(F₆C₆O):

In further specific examples, precursor polymers may be used which arebased on poly(p-phenylene vinylene) derivatives, such as for examplealkoxy poly(p-phenylene vinylene) (alkoxy-PPV) derivatives such as e.g.precursor polymers based onpoly(2-methoxy,5-3′,7′-dimethyloctyloxy)-1,4-phenylene vinylene(MDMO-PPV or OC₁C₁₀PPV), or based on poly(p-thienylene vinylene) (PTV)derivatives.

A method comprises the steps of:

-   -   providing a monomer having the general formula

wherein Ar is an aromatic divalent group or a heteroaromatic divalentgroup, wherein R₀ is an organic group selected from the group consistingof an amine —NR₁R₂, a C₅-C₂₀ alkyloxy group, an aryloxy group, an alkylgroup, an aryl group, an alkylaryl group, an arylalkyl group, athioether group, an ester group, an acid carboxylic group, and aheterocyclic group, and

-   -   reacting said monomer with a basic compound in the presence of        an organic solvent to obtain said precursor polymer,        hereby not requiring the use of a chain end controlling        additive.

In a specific embodiment, a monomer may be provided, having the formulaaccording to formula (I), wherein R₀ is an amine —NR₁R₂, in which R₁ andR₂ are independently from each other an organic group selected from thegroup consisting of a C₁-C₂₀-alkyl group, a cyclic C₃-C₂₀-alkyl group,an aryl group, an alkylaryl group, an arylalkyl group and a heterocyclicgroup, R₁ and R₂ may be linked together to form a cycle.

The basic compound may be selected from the group consisting of a metaloxide, a metal alkoxide, a metal amide, organometal compounds, grignardreagents and ammonium hydroxide. The amount of basic compound may bebetween 1 and 2 equivalents with respect to the monomer.

The concentration of the monomer used in the method may be between 0.1and 0.3 M.

In an embodiment of the first aspect, the Ar group may be an aromaticdivalent group with 4 to 20 carbon atoms which may be substituted withone or more substituents independently selected from the groupconsisting of C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy or C₁-C₂₀-alkylsulfate,poly(ethylene oxide) (PEO) or oligo(ethylene oxide), poly(ethyleneglycol) (PEG) or oligo(ethylene glycol). These aromatic divalent groupsmay comprise up to 4 heteroatoms chosen from the group comprisingoxygen, sulphur, and nitrogen.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,5-furanediyl;2,5-pyrrolediyl; 1,3,4-oxadiazole-2,5-diyl; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar is1,4-phenylene or 2,5-thienylene and most preferably Ar is2,5-thienylene.

In a preferred embodiment, R₁ and R₂ may be a C₁-C₂₀-alkyl group. Inanother embodiment, R₁ and R₂ may be selected from the group consistingof methyl, ethyl and isopropyl.

In a further embodiment of the first aspect, reacting the monomer with abasic compound may be performed at a temperature between −78° C. and200° C., preferably between −40° C. and 120° C., and most preferablybetween −20° C. and 30° C. The temperature may be selected such that theaverage molecular weight of the soluble precursor polymer is as high aspossible and that the polydispersity is as low as possible.

The method as described in the first aspect may require symmetricalstarting monomers. Symmetrical starting molecules have the advantagethat they are easier to synthesise than asymmetric starting monomers.Furthermore, symmetrical starting monomers with dithiocarbamate groupsare stable in time. The polymerisation of the symmetrical monomer in asolvent and in the presence of a base may lead to a precursor polymersoluble in common organic solvents. Those solvents may be polar, apolarand mixtures thereof. The solvent may for example be an aprotic solvent.The dithiocarbamate groups act as a leaving group and as a polarizerduring the polymerisation.

Furthermore, an embodiment provides a precursor polymer with theformula:

wherein Ar is an aromatic divalent group or heteroaromatic divalentgroup, wherein R₀ is an organic group selected from the group consistingof an amine —NR₁R₂, a C₅-C₂₀ alkyloxy group, an aryloxy group, an alkylgroup, an aryl group, an alkylaryl group, an arylalkyl group, athioether group, an ester group, an acid carboxylic group or aheterocyclic group. The C₁-C₂₀-alkyl group, cyclic C₄-C₂₀-alkyl group,phenyl group and benzyl group may comprise heteroatoms and substituents.In a preferred embodiment, R₁ and R₂ may independently be selected frommethyl, ethyl or propyl. R₃ and R₄ are chosen from the group comprisinga hydrogen atom and a C₁-C₂₀-alkyl group, a cyclic C₄-C₂₀-alkyl group, aphenyl group and a benzyl group, which groups may comprise heteroatomsand substituents. In a preferred embodiment, R₃ and R₄ may be hydrogen.All possible combinations of Ar, R₀, R₁, R₂, R₃ en R₄ may be included inthis invention.

In a specific embodiment, the precursor polymer may have the formula asformula (II) wherein R₀ is an amine —NR₁R₂:

and in which R₁ and R₂ are independently from each other an organicgroup selected from the group consisting of a C₁-C₂₀-alkyl group, acyclic C₃-C₂₀-alkyl group, an aryl group, an alkylaryl group, anarylalkyl group and a heterocyclic group, R₁ and R₂ may be linkedtogether to form a cycle. One typical example of such a precursorpolymer may be a precursor polymer wherein R₀=—NR₁R₂ and whereinR₁=R₂=Et:

In other specific examples of precursor polymers which may be used inembodiments, R₀ may be a phenyl group, a methyl group or a group(F₆C₆O):

In other specific examples, precursor polymers may be based on poly(p-Hmissing on C—R4 for each structure!! phenylene vinylene) derivatives,such as for example alkoxy poly(p-phenylene vinylene) (alkoxy-PPV)derivatives such as e.g.poly(2-methoxy,5-3′,7′-dimethyloctyloxy)-1,4-phenylene vinylene(MDMO-PPV or OC₁C₁₀PPV), or on poly(p-thienylene vinylene) derivatives.

In a preferred embodiment, the Ar group may comprise 4 to 20 carbonatoms. In another embodiment, the Ar groups may be substituted with asubstituent chosen from the group consisting of a C₁-C₂₀-alkyl,C₃-C₂₀-alkoxy, C₁-C₂₀-alkylsulfate, poly(ethylene oxide) (PEO) oroligo(ethylene oxide), poly(ethylene glycol) (PEG) or oligo(ethyleneglycol), a phenyl or a benzyl group and these Ar groups may comprise upto 4 heteroatoms chosen from the group comprising oxygen, sulphur, andnitrogen in the aromatic cyclic system. In other embodiments, thesubstituents may be linear, or cyclic or two substituents may be linkedtogether to form a cycle on the Ar groups. In still a furtherembodiment, the substituents may contain charges, ions, cations oranions.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,4-thienylene;2,3-thienylene; 2,5-furanediyl; 2,5-pyrrolediyl;1,3,4-oxadiazole-2,5-diyl; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar may be1,4-phenylene or 2,5-thienylene and most preferably Ar may be2,5-thienylene.

The precursor polymers may show high molecular weight, between 5000 and500000, more particularly between 7000 and 250000, especially between7500 and 100000 Dalton. Furthermore, the polydispersity of the precursorpolymers may be between 1.5 and 5.5, preferably below 2. The precursorpolymer may be obtained in good overall yields in a reproducible way.Large-scale production may be a possibility.

In a second aspect a method for the preparation of soluble or insolubleconjugated arylene and heteroarylene vinylene polymers is disclosed. Themethod does not require the use of chain end controlling additives. Thesoluble or insoluble conjugated arylene heteroarylene vinylene polymershave the general formula:

wherein Ar is equal to the Ar group in the first aspect.

The method comprises the steps of:

providing at least one precursor polymer having the general formula:

wherein Ar is an aromatic divalent group or an heteroaromatic divalentgroup, wherein R₀ is an organic group selected from the group consistingof an amine —NR₁R₂, a C₅-C₂₀ alkyloxy group, an aryloxy group, an alkylgroup, an aryl group, an alkylaryl group, an arylalkyl group, athioether group, an ester group, an acid carboxylic group, and aheterocyclic group, and wherein R₃ and R₄ are independently from eachother hydrogen or an organic group selected from the group consisting ofa C₁-C₂₀-alkyl group, a cyclic C₃-C₂₀-alkyl group, an aryl group, analkylaryl group, an arylalkyl group, a thioether group, an ester group,an acid carboxylic group and a heterocyclic group, wherein n is thenumber of repeating units, and

subjecting the precursor polymer to a thermal conversion reaction whichcomprises total or partial elimination of the —SC(S)R₀ groups by thermaltreatment at a temperature between 30° C. and 300° C. in solution or inthin film.

In a specific example, a precursor polymer is provided with formula asformula (II) wherein R₀ is an amine —NR₁R₂:

and in which R₁ and R₂ are independently from each other an organicgroup selected from the group consisting of a C₁-C₂₀-alkyl group, acyclic C₃-C₂₀-alkyl group, an aryl group, an alkylaryl group, anarylalkyl group and a heterocyclic group, R₁ and R₂ may be linkedtogether to form a cycle. One typical example of such a precursorpolymer may be a precursor polymer wherein R₀=—NR₁R₂ and whereinR₁=R₂=Et.

In other specific examples of precursor polymers which may be used inembodiments according to the invention, R₀ may be a phenyl group, amethyl group or a group (F₆C₆O):

In other specific examples, precursor polymers may be used which arebased on poly(p-phenylene vinylene) derivatives, such as for examplealkoxy poly(p-phenylene vinylene) (alkoxy-PPV) derivatives such as e.g.poly(2-methoxy,5-3′,7′-dimethyloctyloxy)-1,4-phenylene vinylene(MDMO-PPV or OC₁C₁₀PPV), or on poly(p-thienylene vinylene) derivatives.

The precursor polymer may be synthesized according to the methoddescribed in the first aspect. In one embodiment of the second aspect,the duration of the subjecting step may be lower than 24 hours, lowerthan 8 hours and preferably lower than 3 hours.

In an embodiment of the first aspect, the Ar group may be an aromaticdivalent group with 4 to 20 carbon atoms which may be substituted withone or more substituents independently selected from the groupconsisting of C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy, C₁-C₂₀-alkylsulfate,poly(ethylene oxide) (PEO), poly(ethylene glycol) (PEG), a phenyl groupor a benzyl group. These Ar groups may comprise up to 4 heteroatomschosen from the group comprising oxygen, sulphur, and nitrogen in thearomatic divalent group. Furthermore, these groups may independently belinear, or cyclic or two of these groups may be linked together to forma cycle on the Ar group.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,4 thienylene;2,3 thienylene; 2,5-furanediyl; 2,5-pyrrolediyl;1,3,4-oxadiazole-2,5-diyl; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar is1,4-phenylene or 2,5-thienylene and most preferably Ar is2,5-thienylene.

The conjugated arylene or heteroarylene vinylene polymers may beobtained by thermal conversion of the precursor polymer in which theremaining dithiocarbamate group acts as a leaving group (or evaporatinggroup). The conjugated polymer may show a low structural defect level.

In a preferred embodiment, R₁ and R₂ may be a C₁-C₂₀-alkyl group. Inanother embodiment, R₁ and R₂ may be selected from the group consistingof methyl, ethyl or propyl.

In a preferred embodiment, R₁ and R₂ may be a C₁-C₂₀-alkyl. In anotherembodiment, R₁ and R₂ may be selected from the group consisting ofmethyl, ethyl, propyl or phenyl. In another preferred embodiment, R₃ andR₄ may be hydrogen.

In a preferred embodiment, said conjugated arylene vinylene polymer ispoly (2,5 thienylene vinylene) and its derivatives.

In a further embodiment of the second aspect the precursor polymer maybe dissolved in an organic or non-organic solvent and the conversionreaction or elimination reaction may be performed in solution by thermaltreatment under inert or controlled atmosphere to lead to a soluble orinsoluble conjugated polymer. This method may in generally be used whenthe conjugated polymer is expected to be soluble in organic and/ornon-organic solvents. In a further embodiment according this secondaspect the precursor polymer may be in the form of a thin film precursorpolymer layer and the conversion or elimination reaction step may beperformed under inert or controlled atmosphere or under vacuum by insitu thermal treatment.

In a further embodiment of the second aspect, the precursor polymer maybe dissolved in a solvent, followed by a degassing step.

In a further embodiment of the second aspect, the thermal conversionstep may be performed at a temperature between 30° C. and 300° C.,preferably between 80° C. and 300° C., and most preferably between 115°C. and 250° C.

In a further embodiment of the second aspect the yield of the method maybe between 30% and 90%.

Compared to the Wessling route, the method has the advantage of leadingto polymerisation without gel formation and requiring no toxic gas (likestrong acids) during the conversion reaction.

Compared to the Gilch route, an embodiment has the advantages of leadingto polymers that can also be insoluble in their conjugated form. TheGilch route is a one-pot polymerisation, which only allows the synthesisof soluble conjugated polymers; it is not a precursor route as is thecase in this embodiment.

Compared to the sulfinyl route, an embodiment has the advantages ofleading to stable monomers.

Compared to the Hsieh method (U.S. Pat. No. 5,817,430), the method doesnot require the use of chain end controlling additives to control themolecular weight in order to get soluble conjugated polymers. Contraryto the Hsieh method, which is a side chain approach, the methodaccording to an embodiment is a “precursor method” which does notrequire control of the molecular weight. The resulting precursorpolymers are always soluble polymers, whatever their molecular weight isand are soluble even for very high molecular weight. The relatedconjugated polymer may be obtained in a second step by a conversion orelimination reaction under thermal treatment to lead to soluble orinsoluble conjugated polymers. When the conjugated polymer is expectedto be insoluble, the elimination reaction may preferably be carried outin thin film. When the conjugated polymer is expected to be soluble, theelimination reaction may be carried out either in solution or in thinfilm.

Precursor polymers synthesised from a monomer having a symmetricalstructure may be much easier to synthesise and to obtain in good yield.No complicated purification step by chromatography column of the monomeris requested.

Precursor polymers with leaving groups (e.g. dithiocarbamate) arecompatible with a device application. The lifetime of the device is notinfluenced by remaining traces of leaving groups in the active layerafter the conversion reaction.

During the conversion step, the leaving groups of the precursor polymersare eliminated and double bonds of the conjugated polymer are formed. Inone embodiment, substantially all of the leaving groups are eliminated,thus forming a fully converted conjugated polymer. However, in anotherembodiment, only between 90 and 100% of the leaving groups may beeliminated. Hence, between 0 and 10% of the leaving groups is stillpresent in the resulting conjugated polymer. Thus, the resulting polymeris only partially converted. This polymer will be referred to aspartially converted conjugated polymer. The amount of remaining leavinggroups in the partially converted conjugated polymer may be controlledby changing the experimental circumstances of the conversion reaction.

Compared to the bis-sulfide route (EP 1 290 059 A1), the method has theadvantage of leading to polymers by means of polymerisation of monomerswhich are much more stable and therefore allow the synthesis of polymersfor which the instability of the monomers can be a problem to obtainsuch polymer in a reliable way. In the bis-sulfide route, over-oxidationcan occur easily as the oxidation of the sulfide groups is carried outafter polymerisation and not on the starting monomer. Structural defectshave a negative effect on the charge mobility of conjugated polymers

Compared to the bis-xanthate route, an embodiment has the advantages ofleading to:

-   -   monomers and soluble precursor polymers stable in time in inert        atmosphere.    -   precursors and conjugated polymers with a much lower        polydispersity around 2 to 3 (while being between 20 and 30 for        the xanthate-route).    -   reproducibility between batches.    -   precursor polymers obtained through polymerisation reaction        carried out at a temperature ranging from −78° C. to 30° C.    -   the yield of the polymerisation reaction is higher than 50%.    -   conjugated polymers with low defect level.    -   polymers with an increase of λ_(max) of about 20 nm for a PTV        derivative at room temperature synthesised according to an        embodiment, compared to the same PTV derivative synthesised via        another method. For example, poly(2,5-thienylene vinylene),        having no substituent on Ar, has a λ_(max) value around 545 nm        for PTV at high temperature and 570 nm at room temperature when        synthesised according to the method of an embodiment compared to        the same poly(2,5-thienylene vinylene) having no substituents on        Ar which has a λ_(max) value around 500-520 nm at high        temperature when synthesised via the xanthate-route and the        λ_(max) value may be varied from batch to batch.    -   large-scale synthesis is possible.

Furthermore, an embodiment provides a conjugated arylene orheteroarylene vinylene polymer with the general formula:

wherein Ar is an aromatic group or an heteroaromatic divalent group,wherein R₃ and R₄ are independently from each other hydrogen or anorganic group selected from the group consisting of a C₁-C₂₀-alkylgroup, a cyclic C₃-C₂₀-alkyl group, an aryl group, an alkylaryl group,an arylalkyl group and a heterocyclic group, and wherein n is an integerfrom 5 to 2000 and which are formed with the method according to anembodiment.

In a preferred embodiment, Ar comprises 4 to 20 carbon atoms. In anotherembodiment, the Ar groups may be substituted with a substituent chosenfrom the group consisting of a C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy,C₁-C₂₀-alkylsulfate, poly(ethylene oxide) (PEO), poly(ethylene glycol)(PEG), a phenyl or a benzyl group and the Ar groups may comprise up to 4heteroatoms chosen from the group comprising oxygen, sulphur, andnitrogen in the aromatic cyclic system.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,4-thienylene;2,3-thienylene; 2,5-furanediyl; 2,5-pyrrolediyl;1,3,4-oxadiazole-2,5-diyl; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar may be1,4-phenylene or 2,5-thienylene and most preferably Ar may be2,5-thienylene.

All possible combination of Ar, R₀, R₁, R₂, R₃ and R₄ are included inthis invention.

The conjugated polymers, prepared according to a method described in theprevious embodiments has less defects with respect to the prior art.

In a specific, preferred embodiment, the conjugated arylene orheteroarylene vinylene polymer is a poly(2,5-thienylene vinylene) or PTVpolymer with formula:

Due to the fact that the polymer is prepared by the method as describedherein, the poly(2,5-thienylene vinylene) polymer shows a peak at awavelength higher than 520 nm in the absorption spectrum.

In another embodiment, also other PTV derivatives, which have sidechains on the 2 and 3 positions (instead of on the 2 and 5 positions inthe previous embodiment) on the thiophene ring may be used.

In a preferred embodiment, the polymer may be characterized by a peak ata wavelength higher than 540 nm in the absorption spectrum.

The average molecular weight of the polymer may be between 5000 daltonsand 500000 daltons, whereas the polydispersity may be between 1.5 and5.5. Furthermore, the polymer may be a linear polymer.

The method according to an embodiment does not require the use of achain end controlling additive.

In an embodiment at least two monomers having formula (I) may bepolymerised together to form a copolymer.

In a third aspect, an electronic device is provided. The electronicdevice comprises a thin layer of conjugated polymer synthesisedaccording to an embodiment and having the formula (III). Ar, R₃ and R₄are equal to Ar, R₃ and R₄ as described in the first and the secondaspect. The electronic device according to the third aspect has severaladvantages. The polymers were found to have less defects. As a result,the polymer has better properties, resulting in a better electronicdevice.

In a first embodiment of the third aspect, the device may be alight-emitting diode. The light-emitting diode may comprise polymershaving structural units of formula (III). Preferably, Ar may be1,4-phenylene or 2,5-thienylene while R₃ and R₄ may be hydrogen.

In a further embodiment, the device may be a circuit or organictransistor. The integrated circuit may comprise polymers havingstructural units of formula (III), wherein Ar preferably may be1,4-phenylene or 2,5-thienylene while R₃ and R₄ may be hydrogen. Suchintegrated circuits have the advantage of having a lower cost price.According to an embodiment, the device may also be a chemical sensor ora biological sensor

The invention further relates to a method of manufacturing a layer of apolymer with structural units having the formula (II) or (III).

An embodiment further relates to a method of manufacturing bilayerheterojunction organic solar cells using a soluble precursor polymercontaining structural units of formula (II). The active layer made fromthe soluble precursor polymer may become effectively active only afterconversion reaction towards the related soluble or insoluble conjugatedpolymer by an elimination reaction under heat treatment in situ in thinfilm.

Furthermore, an embodiment relates to a method of manufacturing organicbulk heterojunction solar cells using as an active layer a blend of ann-type material, such as a soluble C₆₀ derivatives, and a p-typematerial, such as a precursor polymer containing structural units offormula (II). The active layer made from the n-type/p-type materialblend may become an active layer only after the conversion reaction ofthe thin film by heat treatment.

The invention further relates to a method of manufacturing organictransistors using a polymer containing structural units of formula (II).The active layer made from the soluble precursor polymer may becomeeffectively active after conversion reaction towards the soluble orinsoluble conjugated polymer by elimination reaction of the leavinggroups and formation of the vinylene double bonds by heat treatment.

In a fourth aspect, a method for manufacturing an electronic device isdisclosed. The electronic device comprises a polymer layer. In themethod according to an embodiment, a layer comprising the solubleprecursor polymer (II) is deposited. In a next step, the conjugatedpolymer (III) layer is obtained by carrying out the conversion reactionof the coated soluble precursor polymer layer towards the active solubleor insoluble conjugated polymer by elimination of the leaving groups andformation of the vinylene doubled bonds induced by heat treatment.

On the active soluble or insoluble conjugated polymer layer a furtherannealing treatment may be carried out in order to remove stresses ofthe polymer chains introduced during the deposition of the thin filmlayer and in order to induce a relaxation of the polymer chains andchanges in the polymer film morphology. This annealing may be carriedout before or after the electrode deposition on top of the activeconjugated polymer layer.

These and other characteristics, features and advantages of the presentinvention will become apparent from the following detailed description.

DEFINITIONS

As used herein with respect to a substituting radical, and unlessotherwise stated, the terms “C₁₋₇ alkyl” or “aliphatic saturatedhydrocarbon radicals with 1 to 7 carbon atoms” means straight andbranched chain saturated acyclic hydrocarbon monovalent radicals havingfrom 1 to 7 carbon atoms such as, for example, methyl, ethyl, propyl,n-butyl, 1-methylethyl (isopropyl), 2-methylpropyl (isobutyl),1,1-dimethylethyl (ter-butyl), 2-methylbutyl, n-pentyl, dimethylpropyl,n-hexyl, 2-methylpentyl, 3-methylpentyl, n-heptyl and the like; the term“C₁₋₄ alkyl” designate the corresponding radicals with only 1 to 4carbon atoms, and so on.

As used herein with respect to a substituting radical, and unlessotherwise stated, the term “C₁₋₇ alkylene” means the divalenthydrocarbon radical corresponding to the above defined C₁₋₇ alkyl, suchas methylene, bis(methylene), tris(methylene), tetramethylene,hexamethylene and the like.

As used herein with respect to a substituting radical, and unlessotherwise stated, the terms “C₃₋₁₀ cycloalkyl” and “cycloaliphaticsaturated hydrocarbon radical with 3 to 10 carbon atoms” mean a mono- orpolycyclic saturated hydrocarbon monovalent radical having from 3 to 10carbon atoms, such as for instance cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclooctyl and the like, or a C₇₋₁₀ polycyclicsaturated hydrocarbon monovalent radical having from 7 to 10 carbonatoms such as, for instance, norbornyl, fenchyl, trimethyltricycloheptylor adamantyl.

As used herein with respect to a substituting radical, and unlessotherwise stated, the terms “aryl” and “aromatic substituent” areinterchangeable and designate any mono- or polycyclic aromaticmonovalent hydrocarbon radical having from 6 up to 30 carbon atoms suchas but not limited to phenyl, naphthyl, anthracenyl, phenantracyl,fluoranthenyl, chrysenyl, pyrenyl, biphenylyl, terphenyl, picenyl,indenyl, biphenyl, indacenyl, benzocyclobutenyl, benzocyclooctenyl andthe like, including fused benzo-C₄₋₈ cycloalkyl radicals (the latterbeing as defined above) such as, for instance, indanyl,tetrahydronaphthyl, fluorenyl and the like, all of the said radicalsbeing optionally substituted with one or more substituents selected fromthe group consisting of halogen, amino, nitro, hydroxyl, sulfhydryl andnitro, such as for instance 4-fluorophenyl, 4-chlorophenyl,3,4-dichlorophenyl, 4-cyanophenyl.

As used herein with respect to a substituting radical (including thecombination of two substituting radicals), and unless otherwise stated,the term “heterocyclic” means a mono- or polycyclic, saturated ormono-unsaturated or polyunsaturated monovalent hydrocarbon radicalhaving from 2 up to 15 carbon atoms and including one or moreheteroatoms in one or more heterocyclic rings, each of said rings havingfrom 3 to 10 atoms (and optionally further including one or moreheteroatoms attached to one or more carbon atoms of said ring, forinstance in the form of a carbonyl or thiocarbonyl or selenocarbonylgroup, and/or to one or more heteroatoms of said ring, for instance inthe form of a sulfone, sulfoxide, N-oxide, phosphate, phosphonate orselenium oxide group), each of said heteroatoms being independentlyselected from the group consisting of nitrogen, oxygen, sulfur, seleniumand phosphorus, also including radicals wherein a heterocyclic ring isfused to one or more aromatic hydrocarbon rings for instance in the formof benzo-fused, dibenzo-fused and naphto-fused heterocyclic radicals;within this definition are included heterocyclic radicals such as, butnot limited to, diazepinyl, oxadiazinyl, thiadiazinyl, dithiazinyl,triazolonyl, diazepinonyl, triazepinyl, triazepinonyl, tetrazepinonyl,benzoquinolinyl, benzothiazinyl, benzothiazinonyl, benzoxathiinyl,benzodioxinyl, benzodithiinyl, benzoxazepinyl, benzo-thiazepinyl,benzodiazepinyl, benzodioxepinyl, benzodithiepinyl, benzoxazocinyl,benzothiazocinyl, benzodiazocinyl, benzoxathiocinyl, benzo-dioxocinyl,benzotrioxepinyl, benzoxathiazepinyl, benzoxadiazepinyl,benzothiadiazepinyl, benzotriazepinyl, benzoxathiepinyl,benzotriazinonyl, benzoxazolinonyl, azetidinonyl, azaspiroundecyl,dithiaspirodecyl, selenazinyl, selenazolyl, selenophenyl, hypoxanthinyl,azahypoxanthinyl, bipyrazinyl, bipyridinyl, oxazolidinyl,diselenopyrimidinyl, benzodioxocinyl, benzopyrenyl, benzopyranonyl,benzophenazinyl, benzoquinolizinyl, dibenzocarbazolyl, dibenzoacridinyl,dibenzophenazinyl, dibenzothiepinyl, dibenzooxepinyl, dibenzopyranonyl,dibenzoquinoxalinyl, dibenzothiazepinyl, dibenzoisoquinolinyl,tetraazaadamantyl, thiatetraazaadamantyl, oxauracil, oxazinyl,dibenzothiophenyl, dibenzofuranyl, oxazolinyl, oxazolonyl, azaindolyl,azolonyl, thiazolinyl, thiazolonyl, thiazolidinyl, thiazanyl,pyrimidonyl, thiopyrimidonyl, thiamorpholinyl, azlactonyl,naphtindazolyl, naphtindolyl, naphtothiazolyl, naphtothioxolyl,naphtoxindolyl, naphtotriazolyl, naphtopyranyl, oxabicycloheptyl,azabenzimidazolyl, azacycloheptyl, azacyclooctyl, azacyclononyl,azabicyclononyl, tetrahydrofuryl, tetrahydropyranyl, tetrahydropyronyl,tetrahydroquinoleinyl, tetrahydrothienyl and dioxide thereof,dihydrothienyl dioxide, dioxindolyl, dioxinyl, dioxenyl, dioxazinyl,thioxanyl, thioxolyl, thiourazolyl, thiotriazolyl, thiopyranyl,thiopyronyl, coumarinyl, quinoleinyl, oxyquinoleinyl, quinuclidinyl,xanthinyl, dihydropyranyl, benzodihydrofuryl, benzothiopyronyl,benzothiopyranyl, benzoxazinyl, benzoxazolyl, benzodioxolyl,benzodioxanyl, benzothiadiazolyl, benzotriazinyl, benzothiazolyl,benzoxazolyl, phenothioxinyl, phenothiazolyl, phenothienyl(benzothiofuranyl), phenopyronyl, phenoxazolyl, pyridinyl,dihydropyridinyl, tetrahydropyridinyl, piperidinyl, morpholinyl,thiomorpholinyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl,tetrazinyl, triazolyl, benzotriazolyl, tetrazolyl, imidazolyl,pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, oxazolyl, oxadiazolyl,pyrrolyl, furyl, dihydrofuryl, furoyl, hydantoinyl, dioxolanyl,dioxolyl, dithianyl, dithienyl, dithiinyl, thienyl, indolyl, indazolyl,benzofuryl, quinolyl, quinazolinyl, quinoxalinyl, carbazolyl,phenoxazinyl, phenothiazinyl, xanthenyl, purinyl, benzothienyl,naphtothienyl, thianthrenyl, pyranyl, pyronyl, benzopyronyl,isobenzofuranyl, chromenyl, phenoxathiinyl, indolizinyl, quinolizinyl,isoquinolyl, phthalazinyl, naphthiridinyl, cinnolinyl, pteridinyl,carbolinyl, acridinyl, perimidinyl, phenanthrolinyl, phenazinyl,phenothiazinyl, imidazolinyl, imidazolidinyl, benzimidazolyl,pyrazolinyl, pyrazolidinyl, pyrrolinyl, pyrrolidinyl, piperazinyl,uridinyl, thymidinyl, cytidinyl, azirinyl, aziridinyl, diazirinyl,diaziridinyl, oxiranyl, oxaziridinyl, dioxiranyl, thiiranyl, azetyl,dihydroazetyl, azetidinyl, oxetyl, oxetanyl, thietyl, thietanyl,diazabicyclooctyl, diazetyl, diaziridinonyl, diaziridinethionyl,chromanyl, chromanonyl, thiochromanyl, thiochromanonyl, thiochromenyl,benzofuranyl, benzisothiazolyl, benzocarbazolyl, benzochromonyl,benzisoalloxazinyl, benzocoumarinyl, thiocoumarinyl, phenometoxazinyl,phenoparoxazinyl, phentriazinyl, thiodiazinyl, thiodiazolyl, indoxyl,thioindoxyl, benzodiazinyl (e.g. phtalazinyl), phtalidyl, phtalimidinyl,phtalazonyl, alloxazinyl, dibenzopyronyl (i.e. xanthonyl), xanthionyl,isatyl, isopyrazolyl, isopyrazolonyl, urazolyl, urazinyl, uretinyl,uretidinyl, succinyl, succinimido, benzylsultimyl, benzylsultamyl andthe like, including all possible isomeric forms thereof, wherein eachcarbon atom of said heterocyclic ring may be independently substitutedwith a substituent selected from the group consisting of halogen, nitro,C₁₋₇ alkyl (optionally containing one or more functions or radicalsselected from the group consisting of carbonyl (oxo), alcohol(hydroxyl), ether (alkoxy), acetal, amino, imino, oximino, alkyloximino,amino-acid, cyano, carboxylic acid ester or amide, nitro, thio C₁₋₇alkyl, thio C₃₋₁₀ cycloalkyl, C₁₋₇ alkylamino, cycloalkylamino,alkenylamino, cycloalkenylamino, alkynylamino, arylamino,arylalkylamino, hydroxylalkylamino, mercaptoalkylamino, heterocyclicamino, hydrazino, alkylhydrazino, phenylhydrazino, sulfonyl, sulfonamidoand halogen), C₂₋₇ alkenyl, C₂₋₇ alkynyl, halo C₁₋₇ alkyl, C₃₋₁₀cycloalkyl, aryl, arylalkyl, alkylaryl, alkylacyl, arylacyl, hydroxyl,amino, C₁₋₇ alkylamino, cycloalkylamino, alkenylamino,cyclo-alkenylamino, alkynylamino, arylamino, arylalkylamino,hydroxyalkylamino, mercaptoalkylamino, heterocyclic amino, hydrazino,alkylhydrazino, phenylhydrazino, sulfhydryl, C₁₋₇ alkoxy, C₃₋₁₀cycloalkoxy, aryloxy, arylalkyloxy, oxyheterocyclic,heterocyclic-substituted alkyloxy, thio C₁₋₇ alkyl, thio C₃₋₁₀cycloalkyl, thioaryl, thioheterocyclic, arylalkylthio,heterocyclic-substituted alkylthio, formyl, hydroxylamino, cyano,carboxylic acid or esters or thioesters or amides thereof,thiocarboxylic acid or esters or thioesters or amides thereof; dependingupon the number of unsaturations in the 3 to 10 membered ring,heterocyclic radicals may be sub-divided into heteroaromatic (or“heteroaryl”) radicals and non-aromatic heterocyclic radicals; when aheteroatom of the said non-aromatic heterocyclic radical is nitrogen,the latter may be substituted with a substituent selected from the groupconsisting of C₁₋₇ alkyl, C₃₋₁₀ cycloalkyl, aryl, arylalkyl andalkylaryl.

As used herein with respect to a substituting radical, and unlessotherwise stated, the terms “C₁₋₇ alkoxy”, “C₃₋₁₀ cycloalkoxy”,“aryloxy”, “arylalkyloxy”, “oxyheterocyclic”, “thio C₁₋₇ alkyl”, “thioC₃₋₁₀ cycloalkyl”, “arylthio”, “arylalkylthio” and “thioheterocyclic”refer to substituents wherein a C₁₋₇ alkyl radical, respectively a C₃₋₁₀cycloalkyl, aryl, arylalkyl or heterocyclic radical (each of them suchas defined herein), are attached to an oxygen atom or a divalent sulfuratom through a single bond, such as but not limited to methoxy, ethoxy,propoxy, butoxy, pentoxy, isopropoxy, sec-butoxy, tert-butoxy,isopentoxy, cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, thiomethyl,thioethyl, thiopropyl, thiobutyl, thiopentyl, thiocyclopropyl,thiocyclobutyl, thiocyclopentyl, thiophenyl, phenyloxy, benzyloxy,mercaptobenzyl, cresoxy, and the like.

As used herein with respect to a substituting atom, and unless otherwisestated, the term halogen means any atom selected from the groupconsisting of fluorine, chlorine, bromine and iodine.

As used herein with respect to a substituting radical, and unlessotherwise stated, the terms “arylalkyl”, “arylalkenyl” and“heterocyclic-substituted alkyl” refer to an aliphatic saturated orunsaturated hydrocarbon monovalent radical (preferably a C₁₋₇ alkyl orC₂₋₇ alkenyl radical such as defined above) onto which an aryl orheterocyclic radical (such as defined above) is already bonded, andwherein the said aliphatic radical and/or the said aryl or heterocyclicradical may be optionally substituted with one or more substituentsselected from the group consisting of halogen, amino, nitro, hydroxyl,sulfhydryl and nitro, such as but not limited to benzyl, 4-chlorobenzyl,phenylethyl, 1-amino-2-phenylethyl, 1-amino-2-[4-hydroxyphenyl]ethyl,1-amino-2-[indol-2-yl]ethyl, styryl, pyridylmethyl, pyridylethyl,2-(2-pyridyl)isopropyl, oxazolylbutyl, 2-thienylmethyl and2-furylmethyl.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention will be described with respect to particularembodiments but the invention is not limited thereto but only by theclaims.

It is to be noticed that the term “comprising”, used in the claims,should not be interpreted as being restricted to the means listedthereafter; it does not exclude other elements or steps. Thus, the scopeof the expression “a device comprising means A and B” should not belimited to devices consisting only of components A and B. It means thatwith respect to the present invention, the only relevant components ofthe device are A and B.

The compounds referred to in the detailed description may be selectedfrom the compounds described in the following list:

Compound (I) having the general formula:

wherein Ar may be an aromatic or heteroaromatic divalent group. In apreferred embodiment, Ar may comprise 4 to 20 carbon atoms. In anotherembodiment, each of the Ar groups may be substituted with one or moresubstituents independently selected from the group consisting ofC₁-C₂₀-alkyl, C₃-C₂₀-alkoxy, C₁-C₂₀-alkylsulfate, oligo or poly(ethyleneoxide) (PEO), oligo or poly(ethylene glycol) (PEG), a phenyl group or abenzyl group. These Ar groups may comprise up to 4 heteroatoms chosenfrom the group comprising oxygen, sulphur, and nitrogen in the aromaticcyclic system. The substituents on Ar groups may be independentlylinear, or cyclic, or two of these substituents may be linked togetherto form a cycle on the Ar group.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,4-thienylene;2,3-thienylene; 2,5-furanediyl; 2,5-pyrrolediyl;1,3,4-oxadiazole-2,5-diyl; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar may be1,4-phenylene or 2,5-thienylene and most preferably Ar may be2,5-thienylene.

R₀ may be an aromatic divalent group or a heteroaromatic divalent groupconsisting of an amine —NR₁R₂, a C₅-C₂₀ alkyloxy group, an aryloxygroup, an alkyl group, an aryl group, an alkylaryl group, an arylalkylgroup, a thioether group, an ester group, an acid carboxylic group.

In a preferred embodiment, R₀ may be an amine —NR₁R₂, in which R₁ and R₂are independently from each other an organic group selected from thegroup consisting of a C₁-C₂₀-alkyl group, a cyclic C₃-C₂₀-alkyl group,an aryl group, an alkylaryl group, an arylalkyl group and a heterocyclicgroup, R₁ and R₂ may be linked together to form a cycle. Preferably, R₁and R₂ may be independently selected from a methyl group, an ethylgroup, a propyl group, a phenyl group and a benzyl group. The alkylgroup, phenyl group and benzyl group may comprise heteroatoms andsubstituents.Compound (II) having the general formula

wherein Ar may be an aromatic or heteroaromatic divalent group. In apreferred embodiment, Ar may comprise 4 to 20 carbon atoms. In anotherembodiment, each of the recited Ar groups may be substituted with one ormore independently selected substituents chosen from the groupconsisting of a C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy, C₁-C₂₀-alkylsulfate, oligoor poly(ethylene oxide) (PEO), oligo or poly(ethylene glycol) (PEG), aphenyl or a benzyl group and these Ar groups may comprise up to 4heteroatoms chosen from the group comprising oxygen, sulphur, andnitrogen in the aromatic cyclic system. The substituents on the Argroups may be independently linear, or cyclic, or two of these groupsmay be linked together to form a cycle on the Ar group.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,4-thienylene;2,3-thienylene; 2,5-furanediyl; 2,5-pyrrolediyl;1,3,4-oxadiazole-2,5-diyl; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar may be1,4-phenylene or 2,5-thienylene and most preferably Ar may be2,5-thienylene.

R₀ may be an aromatic divalent group or a heteroaromatic divalent groupconsisting of an amine —NR₁R₂, a C₅-C₂₀ alkyloxy group, an aryloxygroup, an alkyl group, an aryl group, an alkylaryl group, an arylalkylgroup, a thioether group, an ester group, an acid carboxylic group.

In a preferred embodiment, R₀ may be an amine —NR₁R₂,

in which R₁ and R₂ are independently from each other an organic groupselected from the group consisting of a C₁-C₂₀-alkyl group, a cyclicC₃-C₂₀-alkyl group, an aryl group, an alkylaryl group, an arylalkylgroup and a heterocyclic group, R₁ and R₂ may be linked together to forma cycle. Preferably, R₁ and R₂ may be independently selected from amethyl group, an ethyl group, a propyl group, a phenyl group and abenzyl group. The alkyl group, phenyl group and benzyl group maycomprise heteroatoms and substituents. One typical example of such aprecursor polymer may be a precursor polymer wherein R₀=—NR₁R₂ andwherein R₁=R₂=Et:

In other specific examples of precursor polymers which may be usedaccording to embodiments, R₀ may be a phenyl group (Ph), a methyl group(CH₃) or a group (F₆C₆O):

In other specific examples, precursor polymers may be based onpoly(p-phenylene vinylene) derivatives, such as for example alkoxypoly(p-phenylene vinylene) (alkoxy-PPV) derivatives such as e.g.poly(2-methoxy,5-3′,7′-dimethyloctyloxy)-1,4-phenylene vinylene(MDMO-PPV or OC₁C₁₀PPV), or on poly(p-thienylene vinylene) (PTV)derivative, and R₃ and R₄ may be chosen from the group comprising ahydrogen atom, a C₁-C₂₀-alkyl group, a cyclic C₄-C₂₀-alkyl group, aphenyl group and a benzyl group, which groups may comprise heteroatomsand substituents. In a preferred embodiment, R₃ and R₄ may be hydrogen.

Compound (III) having the general formula

wherein Ar may be an aromatic or heteroaromatic divalent group. In apreferred embodiment, Ar comprises 4 to 20 carbon atoms. In anotherembodiment, each of the Ar groups may be substituted with one or moreindependently selected substituents chosen from the group consisting ofa C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy, C₁-C₂₀-alkylsulfate, oligo orpoly(ethylene oxide) (PEO), oligo or poly(ethylene glycol) (PEG), aphenyl or a benzyl group and these Ar groups may comprise up to 4heteroatoms chosen from the group comprising oxygen, sulphur, andnitrogen in the aromatic divalent group. The substituents on Ar groupsmay be independently linear, or cyclic, or two of these substituents maybe linked together to form a cycle on the Ar group.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,4-thienylene;2,3-thienylene; 2,5-furanediyl; 2,5-pyrrolediyl;1,3,4-oxadiazole-2,5-diyl; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar may be1,4-phenylene or 2,5-thienylene and most preferably Ar may be2,5-thienylene.

R₃ and R₄ may be chosen from the group comprising a hydrogen atom and aC₁-C₂₀-alkyl group, a cyclic C₄-C₂₀-alkyl group, a phenyl group and abenzyl group, which groups may comprise heteroatoms and substituents. Ina preferred embodiment, R₃ and R₄ may be hydrogen.

Compound (IV) having the general formula

wherein Ar may be an aromatic or heteroaromatic divalent group. In apreferred embodiment, Ar may comprise 4 to 20 carbon atoms. In anotherembodiment, each of the Ar groups may be substituted with one or moresubstituents independently chosen from the group consisting of aC₁-C₂₀-alkyl, C₃-C₂₀-alkoxy, C₁-C₂₀-alkylsulfate, oligo or poly(ethyleneoxide) (PEO), oligo or poly(ethylene glycol) (PEG), a phenyl or a benzylgroup and these Ar groups may comprise up to 4 heteroatoms chosen fromthe group comprising oxygen, sulphur, and nitrogen in the aromaticcyclic system. The substituents on the Ar groups may be independentlylinear, or cyclic, or two of these substituents may be linked togetherto form a cycle on the Ar group.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,4-thienylene;2,3-thienylene; 2,5-furanediyl; 2,5-pyrrolediyl;1,3,4-oxadiazole-2,5-diyl; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar may be1,4-phenylene or 2,5-thienylene and most preferably Ar may be2,5-thienylene.

X may be selected from the group consisting of Cl, Br or F.

R₅ and R₆ may be selected from the group consisting of a C₁-C₂₀-alkylgroup, a cyclic C₄-C₂₀-alkyl group, a phenyl group and a benzyl group,which groups may comprise heteroatoms and substituents.

Compound (V) having the general formulaY—Ar—Y  (V)wherein Y may comprise chloromethyl, bromomethyl or fluoromethyl atomsand wherein Ar may be an aromatic or heteroaromatic divalent group. In apreferred embodiment, Ar may comprise 4 to 20 carbon atoms. In anotherembodiment, each of the Ar groups may be substituted with one or moresubstituents independently chosen from the group consisting of aC₁-C₂₀-alkyl, C₃-C₂₀-alkoxy, C₁-C₂₀-alkylsulfate, oligo or poly(ethyleneoxide) (PEO), oligo or poly(ethylene glycol) (PEG), a phenyl or a benzylgroup and these Ar groups may comprise up to 4 heteroatoms chosen fromthe group comprising oxygen, sulphur, and nitrogen in the aromaticcyclic system. The substituents on the Ar groups may be independentlylinear, or cyclic, or two of these substituents may be linked togetherto form a cycle on the Ar group.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,4-thienylene;2,3-thienylene; 2,5-furanediyl; 2,5-pyrrolediyl;1,3,4-oxadiazole-2,5-diyl; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar may be1,4-phenylene or 2,5-thienylene and most preferably Ar may be2,5-thienylene.

Compound (VI) having the general formula:

wherein Z may be a leaving group. In a preferred embodiment, Z may beselected from the group consisting of Cl, Br, I, —O-Tos, —O-Mes,—O-Triflates, —(NR₁R₁R₁)⁺, —(SR₁R₂)⁺, —OOCR₁ and —SC(S)OR₁. In the aboveformula, Y may be a polarizer group and may be selected form the groupconsisting of —SR₁, —OR₁, —OH, —Cl, —Br, —SO—R₁, —CN, —CO—OR₁ and—S—C(S)OR₁, R₇ and R₈ may independently be —H, R₁, and Ar may be anaromatic or heteroaromatic divalent group. In a preferred embodiment, Armay comprise 4 to 20 carbon atoms. In another embodiment, each of the Argroups may be substituted with one or more substituents independentlychosen from the group consisting of a C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy,C₁-C₂₀-alkylsulfate, oligo or poly(ethylene oxide) (PEO), oligo orpoly(ethylene glycol) (PEG), a phenyl or a benzyl group and these Argroups may comprise up to 4 heteroatoms chosen from the group comprisingoxygen, sulphur, and nitrogen in the aromatic divalent group.

In a further embodiment, the aromatic or heteroaromatic divalent groupmay be selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,5-furanediyl;2,5-pyrrolediyl; 1,3,4-oxadiazole-2,5-diyl; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl. Preferably, Ar may be1,4-phenylene or 2,5-thienylene and most preferably Ar may be2,5-thienylene.

R₁, R₂, R₃ may be equal to R₁, R₂, R₃ as defined for compound (II).

In a first aspect, the synthesis of a soluble precursor polymer (II)starting from the monomer (I) is provided. An embodiment also providesthe synthesis of monomer (I). The second aspect comprises the conversionreaction of the soluble precursor polymer to the related conjugatedpolymer which may be soluble or insoluble depending on the chemicalstructure. The method does not require the use of chain end controllingagents during the polymerisation reaction as the obtained precursorpolymers are always soluble whatever the Ar groups are.

Furthermore, an embodiment comprises the manufacturing of an activelayer from the precursor polymer. The last step is the electronic devicemade from the precursor polymer followed by its conversion reactiontowards the conjugated polymer as pristine material or in blend.

The first aspect thus provides the synthesis of a soluble precursorpolymer (II). Therefore, first a monomer has to be provided. Therefore,as an example and not limiting to the invention, a dithiocarbamic acidsodium salt is added in the solid state to an aromatic or heteroaromaticring structure of the general formula of compound (IV) or to an aromaticor heteroaromatic ring structure with general formula of compound (V) ina mixture of organic solvents. After stirring a few hours at roomtemperature, the reaction product may be extracted with for exampleether and dried over magnesium sulphate. The product of that reaction isan arylene or heteroarylene group bearing two dithiocarbamate groups inpara positions as described in formula (I).

Mono- and bis-dithiocarbamate molecules may in this invention be used asphotoiniferters. An example of such a bifunctional iniferter isp-xylylene bis(N,N-diethyl dithiocarbamate). It was first synthesised in1984 by Otsu et al (T. Otsu, A. Kuriyama, Polym. Bull. 1984, 11, 2,135), and was used for the living radical polymerisation of styrene andmethyl methacrylate. Otsu wrote an extensive review on the iniferterconcept and living radical polymerisation (T. Otsu, J. Polym. Sci., PartA: Polym. Chem. 2000, 38, 12, 2121). The use of p-xylylenebis(N,N-diethyl dithiocarbamate) as a monomer in a polymerisationprocess was not found.

The synthesis of thiophene-2,5-diylbismethylene N,N-diethylthiocarbamate was patented by Nishiyama et al. in 1975 for itsherbicidal activities (Jpn. Tokkyo Koho, No 50004732, 1975), but againno report exists on the use of the dithiocarbamate “thiophene” analogueas a monomer for polymerisation to soluble precursor polymers which maybe converted by thermal elimination (leaving groups eliminated) towardsthe conjugated semiconductors, which may be soluble or insoluble,depending on their chemical structure.

According to the first aspect the monomer having the general formula (I)is reacted with a basic compound in the presence of an organic solventto obtain the soluble precursor polymer (II). It has to be noted that nochain end controlling agents are required to obtain this solubleprecursor polymer (II).

A mixture of different starting monomers of formula (I) may be reactedby using the above method, leading to copolymers. Alternatively, amixture of different starting monomers of formula (I) and of formula(VI) may be polymerised by using this method leading to copolymers.Those copolymers may then be used as polyiniferters in inifertercontrolled free-radical polymerisation to the synthesis of blockcopolymers and grafted polymers.

The precursor polymers in accordance with the formula (II), that may beprepared by an embodiment, preferably may comprise as the Ar group anaromatic or heteroaromatic group chosen from 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,4-thienylene;2,3-thienylene; 2,5-furanediyl; 2,5-pyrrolediyl;1,3,4-oxadiazole-2,5-diyl; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; dibenzothiophene-2,7-diyl; carbazole-2,7-diyl,of which the nitrogen-containing groups may be substituted on thenitrogen atom with a C₁-C₂₂-alkyl or a C₂-C₁₀-aryl group, while in allgroups the R atoms on the aromatic rings may be substituted by a C₁-C₂₂linear, cyclic or branched alkyl group, C₄-C₁₄ aryl group,electron-donating groups such as C₁-C₂₂ alkoxy and alkylthio groups, andhalogen atoms or electron-attracting groups such as cyano, nitro, andester groups, while the C₁-C₁₄ aryl group itself may be substituted byelectron-donating or electron-attracting groups.

The basic compound may be a metal base, an ammonium base or anon-charged base such as amines like for example triethylamine, pyridineand non-ionic phosphazene bases. The metal in these basic compounds maypreferably be an alkali metal or an alkali earth metal, i.e. a metalfrom group I or II. Classes of metal and ammonium bases are metalhydrides, such as NaH or KH, metal hydroxides, such as NaOH, LiOH orKOH, metal alkoxides, such as NaOMe or NaOEt; KotBu; metal amines suchas a lithium-ammonia solution, a sodium-ammonia solution, lithium inmethylamine; metal amides, such as NaNH₂, NaN(SiMe₃)₂,lithiumdiisopropylamide (LDA), organometal compounds wherein the metalis an alkali metal or alkali earth metal, such as for example a C₁₋₂₀alkyl lithium (e.g. n-BuLi) or a C₁₋₂₀ alkyl sodium, Grignard reagents,and ammonium hydroxides. Grignard reagents are organic magnesium halidespreferably dissolved in a non-reactive solvent (typically dry ethylether). The substance is made up of an organic group, e.g. an alkyl oraryl group, joined by a highly polar covalent bond to magnesium, whilethe magnesium is joined by an ionic bond to a halogen ion e.g. bromideor iodide.

The amount of basic compound may vary from 1 to 2 equivalents withrespect to the starting monomer. It may be preferred to use oneequivalent of basic compound because a too high concentration of basiccompound may induce an in situ conversion reaction during thepolymerisation.

In polar aprotic solvents it is preferred to use metal hydrides as theyshow substantially no nucleophilic properties. In polar protic solventsit is preferred to use bases with a pKa larger than the pKa of thesolvent. In this case the solvent is deprotonated and acts as the actualbasic compound. In the method of an embodiment, it may be preferred touse an aprotic solvent. A mixture of solvents may also be used. Examplesof solvents which may be used are for example amides of the generalformula R₅—CONR₆H, amines of the general formula R₇R₇—N—R₈, sulfones ofthe general formula R₈—SO₂—R₉, sulfoxides of the general formulaR₈—SO—R₉, a solvent from the group consisting of alcohols, such as forexample sec-butanol and all linear or branched C_(n)H_(2n+2)O where1≦n≦20, glycols, polyethers, cyclic ethers, unsaturated ethers, whereinR₅, R₆ are the same or different and denote H, a linear or branchedalkyl group, or R₅ and R₆ together are —(CH₂)₂—, —(CH₂)₃—,CH₂—CH═CH₂—CH₂ or —(CH₂)₄—; and R₇ has the meaning of R₅ or is a phenylgroup which is unsubstituted or substituted by halogen, methyl and/ormethoxy groups; and R₈, R₉ are the same or different and have themeaning of R₇, except H, or R₈ and R₉ together are —(CH₂)₂—, —(CH₂)₃—,—(CH₂)₄— or —CH₂—CH═CH—CH₂—.

The concentration of starting monomer (I) may be determined by thesolubility of the monomer (I). All concentration of the starting monomer(I) in a solvent may be used as long as the monomer (I) is still fullysoluble. However, a concentration of between 0.1 M and 0.3 M maygenerally be preferred.

In a preferred embodiment, a solution of the monomer of formula (I) or amixture of at least two monomers of formula (I) at a giving temperaturemay be degassed for a giving time by passing through a continuousnitrogen flow. A basic compound dissolved in an organic solvent may thenbe added in one-go to the stirred monomer solution. The polymer may thenbe precipitated in ice-cold water and extracted, washed and dried. Theprecursor polymer with structural units of formula (II) such obtained isfully soluble in common organic solvents such as for example THF,cyclohexanone, DMF, chloroform, DMSO, toluene, benzene, dichlorobenzene,dichloromethane, acetone, dioxane and shows an average molecular weight(Mw) between 5,000 and 1,000,000 and a polydispersity between 2 and 15measured by gel permeation chromatography relative to polystyrenestandards.

In a second aspect, the precursor polymer (II) formed in the firstaspect, is converted into the corresponding soluble or insolubleconjugated polymer having the general formula (III).

The soluble precursor polymer may be converted into the correspondingconjugated polymer with units of structural formula (III) in two ways:

-   1. by elimination of the leaving groups and formation of the    vinylene double bonds by thermal heating of the precursor polymer    solution under inert atmosphere or-   2. by elimination of the leaving groups and formation of the    vinylene double bonds by thermal heating in thin film. The thin    films are prepared from the soluble precursor polymer by, for    example, spin-coating, drop-casting, ink-jet printing or    doctor-blading or any other film-making techniques, and converted by    heating under vacuum or under inert atmosphere. The conversion in    thin film is preferred when the conjugated polymer is expected to be    insoluble, therefore the conversion of the soluble precursor polymer    towards the conjugated polymer is made in situ in thin film.

In one embodiment, the polymer (III) may be formed by performing theconversion step of the soluble precursor polymer towards the solubleconjugated polymer in solution. The conversion in solution is preferablywhen the conjugated polymer is a soluble polymer. The precursor polymer(II) may be subjected to a thermal conversion step at a temperaturebetween 30° C. and 300° C. The conversion reaction of the precursorpolymer (II) starts around 100° C. and is completed at around 250-300°C. depending on the chemical structure of the polymer. In thisembodiment, the precursor polymer (II) may thus be dissolved in asolvent in a giving concentration, typically 0.1 M, and is degassed bypassing through a continuous nitrogen flow for, for example, 1 hour. Thetemperature may then be increased and the inert atmosphere is maintainedduring the conversion reaction and the cooling down. A typical procedurecomprises heating a ramp from room temperature to the conversiontemperature at 2° C./min, followed by isotherm at the conversiontemperature for 3 hours and cooling down to room temperature. In anotherembodiment, more than one cycle as described above may be applied to thepolymer.

In still another embodiment, the soluble or insoluble conjugated polymer(III) may be formed by performing the conversion step in thin film.Herefore, glass substrates coated with indium tin oxide (ITO) arecleaned with isopropanol in an ultrasonic bath for 20 minutes and driedin nitrogen flow. The precursor polymer (II) may then be coated on theglass substrate from solution. A two-step process may be used. A firststep determines the film thickness and may be done with a closed coverfor, for example, 5 seconds at 600 rpm. In a second step the film may bedried with an open cover for, for example, 2 minutes at 40 rpm.

The conversion of the precursor polymer (II) towards the soluble orinsoluble conjugated polymer in thin film may be done in a glove boxunder inert atmosphere on a hot plate from room temperature to theconversion temperature at 2° C./min followed by 10 minutes at theconversion temperature. The conversion reaction may be carried out alsounder vacuum conditions.

The polymer (III) is preferably kept under inert atmosphere.

In a further embodiment, an annealing treatment of the soluble orinsoluble conjugated polymer in thin film may be carried out at atemperature of between 30° C. and 200° C. during 1 minute to 2 hoursunder vacuum or inert atmosphere in order to remove stresses of thepolymer chains introduced during the deposition of the thin film layerand in order to induce a relaxation of the conjugated polymer chains andto change the conjugated polymer film morphology. No changes occur inthe chemical structure of the conjugated polymer during this annealingtreatment (heat treatment on conjugated polymer), in contrary to theconversion reaction (heat treatment on precursor polymer) whichinvolves, under heating, an elimination of the leaving groups of thesoluble precursor polymer with the formation of vinylene double bonds.This annealing treatment may be carried out before or after theelectrode deposition on top of the active conjugated polymer layer.

According to the previous embodiment, the conversion of the precursorpolymer (II) may be performed until substantially all leaving groups areeliminated. However, a conjugated polymer may not be fully, i.e. 100%,conjugated because there can always be structural defects which can leadto about 2 to 8%, in most cases between 2 to 5%, of the resultingpolymer that has not been conjugated. Therefore, a reference herein to aconjugated polymer may include within its scope a deviation fromcomplete conjugation of about 2 to 5%.

In still another embodiment, the conversion of the precursor polymer maybe performed only partially. Hence, in the resulting partially convertedconjugated polymer, there may still be leaving groups present. Thepercentage of remaining leaving groups within the resulting conjugatedpolymer may be tuned by changing the experimental conditions such as,for example, temperature, conversion time, atmosphere. The amount ofremaining leaving groups may be between 0 and 10%. For example, if thepercentage of the remaining leaving groups is 5%, it means that thereare, in the resulting partially converted conjugated polymer, for 100monomer units 5 monomer units still having a leaving group and 95monomer units not having a leaving group.

In a specific, preferred embodiment, the conjugated arylene orheteroarylene vinylene polymer is a poly(2,5-thienylene vinylene) or PTVpolymer with formula:

Due to the fact that the polymer is prepared by a method as describedherein, the poly(2,5-thienylene vinylene) polymer according to anembodiment shows a peak at a wavelength higher than 520 nm in theabsorption spectrum.

In another embodiment, also other PTV derivatives, which have sidechains on the 2 and 3 positions (instead of on the 2 and 5 positions inthe previous embodiment) on the thiophene ring may be used.

In a third aspect, an electronic device comprising a polymer accordingto formula (III) is disclosed. The electronic devices may be, but arenot limited hereto, for example organic field effect transistors,bilayer heterojunction organic solar cells and bulk heterojunctionorganic solar cells. During the processing of the electronic devices,the precursor polymer (II) may be deposited and subsequently subjectedto a thermal conversion step (according to the second aspect) such thatan active layer may be formed.

According to the third aspect, an organic bulk heterojunction solar cellwith acceptable efficiency may be prepared from the precursor polymer(II). This may be advantageous over prior art methods, where theconjugated polymer is the starting compound and hence must be soluble tobe mixed with a soluble C₆₀ derivative (for example PCBM). As theconversion temperature of the precursor polymer of formula (II) startsrelatively at low temperature (e.g. 100-115° C.), it may be possible toprepare a blend n-type/p-type, used as active layer, by mixing theprecursor polymer (II) with PCBM and then carrying out the conversionreaction by heat treatment in thin film keeping the initial chemicalstructure of PCBM and converting simultaneously the soluble precursorpolymer to the soluble or insoluble conjugated polymer. Furthermore, anyother p-type material being a small molecule or an oligomer or a polymerother than C₆₀ or PCBM and having a chemical structure stable at thetemperature used during the conversion reaction of the precursor polymertowards the conjugated polymer may be also considered.

For the bulk heterojunction solar cells in accordance to the thirdaspect the precursor polymer may contain the structural units of formula(II) wherein R₁, R₂ may be as described in formula (II) and wherein Armay be 2,5-thienylene, which may be substituted on its 3 and 4 positionsby a C₁-C₂₂ linear or branched alkyl group, C₄-C₁₄ aryl group,electron-donating groups such as C₁-C₂₂ linear or branched alkoxy andalkylthio groups, and halogen atoms or electron-attracting groups suchas cyano, nitro, and ester groups, while the C₁-C₁₄ aryl group itselfmay be substituted by electron-donating or electron-attracting groups,and the two substituent groups on the Ar group may be linked together toform a cycle on the Ar group, and a soluble C₆₀ derivative may be usedas n-type material, such as PCBM. The active layer may be obtained bycarrying out the conversion reaction by heat treatment of the thin filmkeeping intact the initial chemical structure of the soluble C₆₀derivative.

A fourth aspect comprises the manufacturing of bilayer organic solarcells, organic transistors and LED's having an active layer made from aprecursor polymer containing structural units of formula (II) which isin situ converted to the active soluble or insoluble conjugated polymer.

Furthermore, bilayer organic solar cells in accordance with the fourthaspect are disclosed wherein the precursor polymer may comprise thestructural units of formula (II) wherein R₀ may be as described informula (II) and wherein Ar may be 2,5-thienylene, which may besubstituted on its 3 and/or 4 positions by a C₁-C₂₂ linear or branchedalkyl group, C₄-C₁₄ aryl group, electron-donating groups such as C₁-C₂₂linear, cyclic or branched alkoxy and alkylthio groups, and halogenatoms or electron-attracting groups such as cyano, nitro, and estergroups, while the C₁-C₁₄ aryl group itself may be substituted byelectron-donating or electron-attracting groups. At least two of theseindependently chosen substituents may, in one embodiment, be linkedtogether to form a cyclic structure on the Ar group between the 3 and 4positions. The active layer may be obtained by carrying out theconversion reaction by heat treatment of the thin film.

Furthermore, organic transistors in accordance with the fourth aspectare disclosed wherein the precursor polymer may comprise the structuralunits of formula (II) wherein R₀ may be as described in formula (II) andwherein Ar may be 2,5-thienylene which may be substituted on its 3 and 4positions by a C₁-C₂₂ linear or branched alkyl group, C₄-C₁₄ aryl group,electron-donating groups such as C₁-C₂₂ linear or branched alkoxy andalkylthio groups, oligo- or poly(ethylene oxide) (PEO), oligo- orpoly(ethylene glycol) (PEG), and halogen atoms or electron-attractinggroups such as cyano, nitro, and ester groups, while the C₁-C₁₄ arylgroup itself may be substituted by electron-donating orelectron-attracting groups. At least two of these independently chosensubstituents may, an one embodiment, be linked together to form a cyclicstructure on the Ar group between the 3 and 4 positions. The activelayer may be obtained by carrying out the conversion reaction of theprecursor polymer towards the related soluble or insoluble conjugatedpolymer by heat treatment of the thin film.

Furthermore, Light emitting diodes (LED) in accordance with the fourthaspect are disclosed wherein the LED may comprise a substrate havingdeposited thereon successively a thin film of a soluble precursorpolymer according to structural formula (II), prepared in accordance tothe first aspect and converted to the conjugated polymer with structuralformula (III) by heat treatment in accordance with the second aspect anda layer of an electrical conductor together with means for biasing thethin film and conductor.

EXAMPLE 1

In a first example the synthesis of p-xylylene bis(N,N-diethyldithiocarbamate) with a formula according to formula (I) whereinAr=1,4-phenylene, R₀=—NR₁R₂ with R₁=R₂=C₂H₅, followed by thepolymerisation to the precursor polymer with a formula according toformula (II) wherein Ar=1,4-phenylene, R₀=—NR₁R₂ with R₁=R₂=C₂H₅,R₃=R₄=H and subsequent conversion to the conjugated polymer with aformula according to formula (III) wherein Ar=1,4-phenylene, R₃=R₄=H isillustrated.

To 50 ml of an acetonitrile/water solution (5% vol water) of1,4-bis(tetrahydrothiopheniomethyl)xylene dichloride (6 g, 17.143 mmol),diethyldithiocarbamic acid sodium salt trihydrate (8.87 g, 39.429 mmol)is added as a solid, after which the mixture is stirred at ambienttemperature for two hours. Then, water is added and the desired monomeris extracted with ether (3×100 ml) and dried over MgSO₄. Evaporation ofthe solvent yields 6.2 g, which is 90%, of the pure product as a whitesolid. ¹H NMR (CDCl₃): 7.31 (s, 4H), 4.49 (s, 4H), 4.01 (q, J=7.2 Hz,4H), 3.69 (q, J=7.2 Hz, 4H), 1.25 (2t, J=7.2 Hz, 12H). ¹³C NMR (CDCl₃):195.10, 135.27, 129.57, 49.46, 46.70, 41.79, 12.44, 11.56; MS (EI, m/e):253 (M⁺−SC(S)NEt₂), 148 (SC(S)NEt₂), 105 (M⁺−2×SC(S)NEt₂), 72 (NEt₂)

A solution of the synthesised monomer p-xylenebis(N,N-diethyldithiocarbamate) (500 mg, 1.25 mmol) in dry THF (6.25 ml,0.2 M) at −78° C. (or RT or 0° C.) is degassed for 1 hour by passingthrough a continuous nitrogen flow. An equimolar LDA solution (625 μl ofa 2 M solution in THF) is added in one go to the stirred monomersolution. The THF from the basic solution is neglected in thecalculation of the monomer concentration. The mixture is then kept at−78° C. (or R.T or 0° C.) for 90 minutes while the passing of nitrogenis continued. After this, the solution is allowed to come to 0° C. orethanol (6 ml) is added at −78° C. to stop the reaction (this is notnecessary if the polymerisation is performed at RT or 0° C.). Thepolymer is then precipitated in ice water (100 ml) and extracted withchloroform (3×60 ml). The solvent of the combined organic layers isevaporated under reduced pressure and a second precipitation isperformed in a 1/1 mixture (100 ml) of diethyl ether and hexane at 0° C.The polymer was collected and dried in vacuum. ¹H NMR (CDCl₃): 6.78-7.14(br s, 4H), 5.00-5.30 (br s, 1H), 3.82-4.10 (br s, 2H), 3.51-3.78 (br s,2H), 2.92-3.12 (br s, 2H), 1.04-1.34 (br t, 6H). ¹³C NMR (CDCl₃):194.38, 138.07, 137.17, 129.35, 128.30, 56.92, 49.15, 46.68, 42.63,12.58, 11.65. The residual fractions only contained monomer residues.Polymerisation experiments are carried out at different temperatures.The results are summarised in table 1. In this table, Mw denotes themolecular weight and PD the polydispersity of the conjugated polymer.

TABLE 1 Starting monomer with structural units of formula (I) with: Ar =1,4-phenylene, R₁ = Et, R₂ = Et in THF. Conc. Polymerisation Yield Mw(M) temp. (° C.) (%) (g/mol) PD 0.2 −78 90 7300 1.5 −78 to 0 88 150002.1 0 87 31200 4.1 RT 88 36500 5.5

EXAMPLE 2

In a second example, the synthesis of thiophene-2,5-diylbismethyleneN,N-diethyl dithiocarbamate with a formula according to formula (I)wherein Ar=2,5-thienylene and R₀=—NR₁R₂ with R₁=R₂=C₂H₅, followed bypolymerisation to the precursor polymer with a formula according toformula (II) wherein Ar=2,5-thienylene, R₀=—NR₁R₂ with R₁=R₂=C₂H₅ andR₃=R₄=H, and subsequent conversion to the conjugated polymer with aformula according to formula (III) wherein Ar=2,5-thienylene andR₃=R₄=H, is illustrated.

The preparation of the monomer is analogous to that described in example1, but here a bis-sulphonium salt of formula (IV) whereAr=2,5-thienylene is used. The yield of the reaction is 81%; ¹H NMR(CDCl₃): 6.84 (s, 2H), 4.69 (s, 4H), 4.01 (q, J=7.2 Hz, 4H), 3.69 (q,J=7.2 Hz, 4H), 1.26 (t, J=7.2 Hz, 12H); ¹³C NMR (CDCl₃): 194.29, 138.76,126.77, 49.46, 46.70, 36.72, 12.46, 11.53; MS (EI, m/e): 258(M⁺−SC(S)NEt₂), 148 (SC(S)NEt₂)

The polymerisation of thiophene-2,5-diylbismethylene N,N-diethyldithiocarbamate is analogous to that described in example 1. ¹H NMR(CDCl₃): 6.56-6.72 (br s, 1H), 6.72-6.36 (br s, 1H), 5.22-5.55 (br s,1H), 3.81-4.12 (br q, 2H), 3.48-3.81 (br q, 2H), 3.11-3.40 (br s, 2H),1.01-1.37 (br t, 6H). ¹³C NMR (CDCl₃): 193.61, 140.77, 140.36, 126.15,125.89, 52.50, 49.20, 46.73, 38.37, 12.45, 11.60.

In this example, polymerisation experiments are carried out at differenttemperatures and with different concentrations of starting monomer. Theresults of these experiments are summarised in table 2.

TABLE 2 Starting monomer with structural units of formula (I) with: Ar =2,5-thienylene, R₁ = Et, R₂ = Et in THF. Conc. Polymerisation Yield Mw(M) temp. (° C.) (%) (g/mol) PD 0.1 −78 47 62800 2.9 −78 to 0 55 900005.3 0 42 23800 3.8 0.2 −78 57 94400 3.1 −78 to 0 56 66100 4.9 0.3 −78 to0 53 12800 1.4

An organic field effect transistor is then prepared according to thefollowing procedure using the soluble precursor polymer synthesised inaccordance with the method described in this embodiment. Field-effecttransistors (FETs) may be made of high doped Si substrates. In thisexample, an isolating oxide (SiO₂) of 100 nm is grown thermally on oneside of the Si substrate, while the backside of the substrate is coveredwith an Al layer which acts as a gate electrode. An organic film is thenapplied on top of the oxide.

This may be done by means of spin-coating a 1% w/v solution of theprecursor polymer (II) in chlorobenzene. Measurements of the holemobility are performed with FETs on which furthermore Au source anddrain electrodes are evaporated after the organic film is applied.Before starting the measurement, the precursor polymer (II) in the formof a thin film is converted to the insoluble conjugated polymerpoly(p-thienylene vinylene) (PTV) by heating the sample from roomtemperature to 185° C. at 2° C. per minute. After the sample is hold at185° C. for 10 minutes, it is cooled back to ambient temperature.

A negative gate-voltage induces an accumulation of positive charges in athin conducting channel on the contact surface of the organic film withthe oxide. The field-effect mobilities are determined from thesaturation regime of the drain-source current with the formula:I_(ds,sat)=μ_(FE)WC_(ox)(V_(gs)−V_(t))²/2L wherein W is the width and Lthe length of the conducting channel respectively, C_(ox) is thecapacity of the isolating SiO₂ layer, V_(gs) is the gate voltage andV_(t) is the threshold voltage.

A bilayer organic heterojunction solar cell is prepared according to thefollowing procedure using the precursor polymer synthesised inaccordance with the method described in this embodiment. TwoITO/PEDOT/PTV/AI devices on glass substrate were tested.

A first test is carried out with a first device wherein pristine is usedan active layer. The second device is made by first converting thespin-coated precursor and afterwards spin-coating [6,6]-PCBM on top ofit, thus forming a bilayer solar cell. J/V curves of the devices in darkand under illumination of 100 mW/cm² light from halogen lamp werestudied. Experimental results of both devices are summarized in table 3.

TABLE 3 Starting monomer with structural units of formula (I) with: Ar =2,5-thienylene, R₁ = Et, R₂ =Et. Pristine Bilayer solar cell J_(sc)(mA/cm²) 430 1430 V_(oc) (mV) 435 515 FF (%) 34 48.5 η (%) 0.06 0.36

Organic heterojunction solar cells are prepared according to thefollowing procedure using the soluble precursor polymer synthesised inaccordance with the method described in this embodiment. Glasssubstrates coated with ITO (resistance ˜90 ohm per square) are firstcleaned with isopropanol in an ultrasonic bath for 20 min and dried in anitrogen flow. The samples are brought into the glove box with anitrogen atmosphere. All following steps now are done inside the glovebox. An 80 nm layer of PEDOT/PSSA is spin-coated on top of the ITO andheat treated for 10 min at 180° C. on a hot plate. Then, the sample iscooled down to room temperature and thereafter the photoactive layer,which is cast from a 0.5 wt.-% solution of precursor polymer of formula(II) mixed with a soluble C₆₀ derivative (PCBM) in chlorobenzene, isspincoated on top of the PEDOT/PSSA. The ratio by weight of theprecursor polymer of formula (II) and PCBM is comprised between 1:0.5and 1:4. The solution is stirred with a magnetic stirrer for 4 hours atroom temperature.

The spincoating of the active layer is a two-step procedure. The firststep, to determine the thickness, is done with a closed cover. Thespinning speed is comprised between 250 rpm and 600 rpm and the spinningtime between 1 and 5 seconds. The second step is to dry the film. Thisstep is performed with an open cover for 3 min at 100 rpm. The convertedfilm may have a thickness between 80 and 100 nm.

The conversion of the soluble precursor polymer, in the example givenblended with PCBM, is done on a hot plate inside the glove box from roomtemperature up to 150° C. with a temperature step of 2° C. per minute.Then, the temperature is kept constant at 150° C. for 5 min. This is theso-called “Conversion reaction” done by heat treatment, here in thinfilm, in which a soluble precursor polymer is chemically converted tothe related conjugated polymer, which might be soluble or insoluble, bythermal induced elimination of the leaving groups and formation of thevinylene double bonds. After that, the top electrode is evaporated in avacuum of 2.10⁻⁶ mbar. First, a 0.7 nm thick layer of LiF and then asecond layer of 150 nm aluminum are evaporated. The active area of eachcell is 6 mm².

Afterwards, the sample is measured with a solar simulator (AM1.5spectrum). Then, a post-production heat treatment, also called annealingtreatment, on a hot plate took place for several times, starting with 5min at 70° C. Then the samples are measured again at room temperatureand after that annealing process again (55 min, in total 1 hour). Fiveannealing steps are done with a total time of 9 hours. The results aremuch higher after 9 hours of annealing than the initially values. Thegoal of the annealing treatment, which is a heat treatment done on thelevel of the conjugated polymer and not at the level of the precursorpolymer, is not a chemical reaction induced by heat but a heatrelaxation process of the conjugated polymer chains to release stressand therefore induces a transformation of the conjugated polymer chainsmorphology.

Example of results found for a Polymer/PCBM ratio of 1:1 withV_(oc)=0.41V; J_(sc)=3.42 mA/cm²; FF=34.4%; η=0.48%.

EXAMPLE 3

A third example describes the synthesis ofthiophene-2,5-diylbismethylene N,N-diethyl dithiocarbamate-3,4-diphenylwith a formula according to formula (I) wherein Ar=3,4-diphenyl2,5-thienylene and R₀=—NR₁R₂ with R₁=R₂=C₂H₅ followed by polymerisationto the precursor polymer with a formula according to formula (II)wherein Ar=3,4-diphenyl 2,5-thienylene and R₃=R₄=H.

For the synthesis of 3,4-Diphenylthiophene, phenylboronic acid (7.12 g,58.394 mmol), 3,4-dibromothiophene (3.05 g, 12.603 mmol) and KF (2.92 g,50.345 mmol) are dissolved in a mixture water and toluene 50/50 (80 mL).Pd(PPh₃)₄ (873 mg) is added as a catalyst. After refluxing the mixturefor 24 hours, an extraction with CHCl₃ (3×50 mL) is performed and thecombined organic phases are dried over MgSO₄. The crude reaction productis purified by column chromatography (silica, n-hexane). The yield is75%; ¹H NMR (CDCl₃): 7.30 (s, 2H), 7.25-7.21 (m, 6H), 7.19-7.16 (m, 4H);MS (EI, m/e): 236 (M⁺)

For the synthesis of 3,4-Diphenyl-2,5-bis chloromethyl thiopheneconcentrated HCl (4.93 g, 50.650 mmol) and acetic anhydride (9.06 g,88.859 mmol) are, under nitrogen atmosphere, added to paraformaldehyde(719 mg, 23.992 mmol) and 3,4-diphenylthiophene (2.1 g, 8.886 mmol) in athree-necked flask. After 4.5 hours refluxing this mixture at 70° C., 10mL of a cold saturated aqueous solution of sodium acetate and 10 mL of a25% aqueous solution of sodium hydroxide are added. The mixture is thenextracted with CHCl₃ (3×50 mL) and dried over MgSO₄. The yield of theprocess is 98%. ¹H NMR (CDCl₃): 7.24-7.21 (m, 6H), 7.08-7.05 (m, 4H),4.67 (s, 4H); MS (EI, m/e): 332 (M⁺), 297 (M⁺−Cl), 261 (M⁺−2Cl)

For the synthesis of 3,4-diphenylthiophene-2,5-diylbismethyleneN,N-diethyl dithiocarbamate a mixture of3,4-diphenyl-2,5-bischloromethylthiophene (3 g, 8.890 mmol) and sodiumdiethyldithiocarbamate trihydrate (4.6 g, 20.448 mmol) in 10 mL ofmethanol is stirred for three hours at room temperature. The mixture isthen extracted with CHCl₃ (3×50 mL), dried over MgSO₄ and after thesolvent is evaporated, 3.5 g (70% yield) of dithiocarbamate monomer isobtained as a pink solid. ¹H NMR (CDCl₃): 7.24-7.14 (m, 6H), 7.03-7.00(m, 4H), 4.62 (s, 4H), 4.01 (q, J=7.2 Hz, 4H), 3.69 (q, J=7.2 Hz, 4H),1.26 (2t, J=7.2 Hz, 12H). ¹³C NMR (CDCl₃): 194.22, 141.14, 135.33,133.39, 129.99, 127.82, 126.77, 49.31, 46.63, 35.82, 12.39, 11.43.

A solution of the synthesised monomer (400 mg, 0.716 mmol) in dry THF(3.6 ml, 0.2 M) at −78° C. (or room temperature or 0° C.) is degassedfor 15 minutes by passing through a continuous nitrogen flow. Anequimolar LDA solution (360 μL of a 2 M solution in THF/n-hexane) isthen added in one go to the stirred monomer solution. The mixture iskept at −78° C. (or room temperature or 0° C.) for 90 minutes and thepassing of nitrogen is continued. After this, the solution is allowed tocome to 0° C. or ethanol (6 ml) is added at −78° C. to stop the reaction(this is not necessary if the polymerisation is performed at R.T or 0°C.). The polymer is precipitated in ice water (100 ml) and extractedwith chloroform (3×60 ml). The solvent of the combined organic layers isevaporated under reduced pressure and a second precipitation isperformed in MeOH. The precursor polymer is collected and dried invacuum. ¹H NMR (CDCl₃): 6.78-7.14 (br s, 4H), 5.00-5.30 (br s, 1H),3.82-4.10 (br s, 2H), 3.51-3.78 (br s, 2H), 2.92-3.12 (br s, 2H),1.04-1.34 (br t, 6H). ¹³C NMR (CDCl₃): 194.38, 138.07, 137.17, 129.35,128.30, 56.92, 49.15, 46.68, 42.63, 12.58, 11.65.

TABLE 4 Starting monomer with structural units of formula (I) wherein Ar= 3,4-diphenyl-2,5-thienylene, R₁ = Et, R₂ = Et in THF. Conc.Polymerisation Yield Mw (g/mol) (M) temp. (° C.) (%) in DMF PD 0.2 0 3050400 1.4 −78 60 29800 1.2 −78 to 0 50 24600 1.2

EXAMPLE 4

In a fourth example, a co-polymerisation reaction between p-xylenebis(N,N-diethyldithiocarbamate) (Formula (I) wherein Ar is a thiophenering and R₁=R₂=C₂H₅ and further denoted as A) and2,5-bis[ethoxy(thiocarbonyl)thiomethyl]thiophene (Formula (VI) whereinAr is a thiophene ring, R₇=R₈=H and Y=Z=SC(S)OEtEt, and further denotedas B) is illustrated.

A solution of monomer p-xylene bis(N,N-diethyldithiocarbamate) (375,250, 125 mg respectively) and monomer2,5-bis[ethoxy(thiocarbonyl)thiomethyl]thiophene (108, 217, 325 mgrespectively) in dry THF (6.16 ml, 0.2 M) at −78° C. is degassed for 1hour by passing through a continuous nitrogen flow. An equimolar LDAsolution (616 μl of a 2 M solution in THF) is added in one go to thestirred monomer solution. The mixture is kept at −78° C. for 90 minutesand the passing of nitrogen is continued. After this, ethanol (6 ml) isadded at −78° C. to stop the reaction. The polymer is precipitated inice water (100 ml) and extracted with chloroform (3×60 ml). The solventof the combined organic layers is evaporated under reduced pressure anda second precipitation is performed in a 1/1 mixture (100 ml) of diethylether and hexane at 0° C. The polymer is collected and dried in vacuum.

Experiments are carried out at different ratios of A and B. The resultsare summarised in table 5.

TABLE 5 Starting monomer as a mixture of monomer with structural unitsof formula (I) wherein Ar = 2,5-thienylene, R₁ = Et, R₂ = Et, (A), andof monomer with structural units of formula (VI) wherein Ar =2,5-thienylene, R₇ = R₈ = H and Y = Z = SC(S)OEtEt, (B) Yield Mw MolarRatio A/B (%) (g/mol) PD 100/0  57 94400 3.1 75/25 56 372600 13.3 50/5069 309900 12.8 25/75 70 202700 10.3  0/100 50 137200 7.8

EXAMPLE 5

In a fifth example, the synthesis of 2,5-bis(N,N-diethyldithiocarbamate)-1-(3,7-dimethyloctyloxy)-4-methoxybenzene with aformula according to formula (I) whereinAr=1-(3,7-dimethyloctyloxy)-4-methoxy-2,5-phenylene, R₀=—NR₁R₂,R₁=R₂=C₂H₅, followed by the polymerisation to the soluble precursorpolymer with a formula according to formula (II) whereinAr=1-(3,7-dimethyloctyloxy)-4-methoxy-2,5-phenylene, R₃=R₄=H, isillustrated.

To 50 ml of an ethanol solution of2,5-bis(chloromethyl)-1-(3,7-diemthyloxtyloxy)-4-methoxybenzene (5 g,13.889 mmol), diethyl dithiocarbamic acid sodium salt trihydrate (7.19g, 31.944 mmol) is added as a solid, after which the mixture is stirredat ambient temperature for three hours. Then, water is added and thedesired monomer is extracted with ether (3×100 ml) and dried over MgSO₄.Evaporation of the solvents yields 92% of the pure product as a whitesolid. ¹H NMR (CDCl₃): 6.99 (s, 2H), 4.52 (s, 2H), 4.48 (s, 2H), 3.95(m, 4H+2H), 3.74 (s, 3H), 3.64 (m, 4H), 1.60-1.85 (m, 2H), 1.38-1.58 (m,2H), 1.21 (t, 12H), 1.05-1.30 (m, 6H), 0.88 (d, 3H), 0.81 (d, 6H); ¹³CNMR (CDCl₃): 196.11, 195.99, 151.27, 150.90, 125.08, 124.42, 114.75,113.86, 67.13, 56.19, 49.41, 49.34, 46.61, 39.22, 37.32, 36.83, 36.30,29.79, 27.95, 24.69, 22.69, 22.59, 19.62, 12.42, 11.59

The polymerisation reaction is analogous to that described in example 1.Polymerisation experiments are carried out at different temperatures.The results are summarised in table 6.

TABLE 6 Starting monomer with structural units of formula (I) wherein Ar= 1-(3,7-dimethyloctyloxy)-4-methoxy-2,5-phenylene, R₀ = —NR₁R₂ with R₁= R₂ = C₂H₅ in THF Polymerisation Yield Mw (g/mol) PD temperature (%)(in DMF) (in DMF) −78° C. 54 3800 1.0 Room temperature 59 14900 2.8 6918400 2.9  35° C. 62 18900 2.9  65° C. 39 37100 1.4

EXAMPLE 6

A sixth example describes the synthesis of pyridine-2,5-diylbismethyleneN,N-diethyl dithiocarbamate with a formula according to formula (I)wherein Ar=2,5-pyridine, R₀=—NR₁R₂, R₁=R₂=C₂H₅, followed by thepolymerisation to the soluble precursor polymer with a formula accordingto formula (II) wherein Ar=2,5-pyridine, R₃=R₄=H.

The yield of the reaction is 82%. ¹H NMR (CDCl₃): 8.54 (d, 1H), 7.86 (d,1H), 7.63 (d, 1H), 4.88 (s, 2H), 4.56 (s, 2H), 4.00 (q, 4H), 3.72 (q,4H), 1.26 (2t, 12H); MS (EI, m/e): 401 (M⁺), 285 (M⁺−C(S)NEt₂), 148(SC(S)NEt₂), 116 (C(S)NEt₂).

The polymerisation reaction is analogous to that described in example 1.Polymerisation experiments are carried out at room temperature and 35°C. The results are summarised in table 7.

TABLE 7 Starting monomer with structural units of formula (I) wherein Ar= 2,5-pyridine, R₀ = —NR₁R₂ with R₁ = R₂ = C₂H₅ in THF PolymerisationYield Mw (g/mol) PD temperature (%) (in DMF) (in DMF) Room temperature43 14800 2.0 35° C. 40 15800 2.1

EXAMPLE 7

In a seventh example, the synthesis of1,4-bis{2-[2-(2-methoxyethoxy)ethoxy]ethoxy}-2,5-diylbismethyleneN,N-diethyl dithiocarbamate with a formula according to formula (I)wherein Ar=1,4-bis-(2-(2-(2-methoxy-ethoxy)-ethoxy)-ethoxy)-benzene,R₀=—NR₁R₂, R₁=R₂=C₂H₅, followed by the polymerisation to the solubleprecursor polymer with a formula according to formula (II) whereinAr=1,4-bis-(2-(2-(2-methoxy-ethoxy)-ethoxy)-ethoxy)-benzene, R₃=R₄=H.

The yield of the reaction is 75%. ¹H NMR (CDCl₃): 7.01 (s, 2H), 4.54 (s,4H), 4.09 (t, 4H), 3.81 (t, 4H), 3.60-3.76 (m, 20H), 3.53 (m, 4H), 3.36(s, 6H), 1.25 (t, 12H); ¹³C NMR (CDCl₃): 195.80, 150.73, 125.30, 115.22,71.84, 70.83, 70.63, 70.47, 69.69, 68.81, 58.95, 49.38, 46.56, 36.48,12.41, 11.57; DIP MS (Cl, m/e): 725 (M⁺), 576 (M⁺−SC(S)NEt₂).

The polymerisation reaction is analogous to that described in example 1.¹H NMR (CDCl₃): 6.69-6.87 (br s, 2H), 5.56-5.76 (br s, 1H), 3.42-4.13(m, 28H), 1.00-1.34 (br t, 6H)

TABLE 8 Starting monomer with structural units of formula (I) wherein Ar= 1,4-bis(2-(2-(2-methoxy-ethoxy)ethoxy)-ethoxy)-benzene, R₀ = —NR₁R₂with R₁ = R₂ = C₂H₅ in THF Polymerisation Yield Mw (g/mol) PDtemperature (%) (in DMF) (in DMF) Room temperature 59 14900 2.8

EXAMPLE 8

In an eighth example, the synthesis of3,4-dichlorothiophene-2,5-diylbismethylene N,N-diethyl dithiocarbamatewith a formula according to formula (I) whereinAr=3,4-dichloro-2,5-thienylene, R₀=—NR₁R₂, R₁=R₂=C₂H₅, followed by thepolymerisation to the soluble precursor polymer with a formula accordingto formula (II) wherein Ar=3,4-dichloro-2,5-thienylene, R₃=R₄=H, isillustrated.

The yield of the reaction is 94%; ¹H NMR (CDCl₃): 4.71 (s, 4H), 4.00 (q,J=7.2 Hz, 4H), 3.69 (q, J=7.2 Hz, 4H), 1.26 (t, J=7.2 Hz, 12H); ¹³C NMR(CDCl₃): 193.58, 131.67, 122.65, 49.80, 46.84, 34.50, 12.52, 11.53; MS(EI, m/e): 326 (M⁺−SC(S)NEt₂), 178 (M⁺−2 SC(S)NEt₂), 148 (SC(S)NEt₂),116 (C(S)NEt₂), 72 (NEt₂).

The polymerisation reaction is analogous to that described in example 1.¹H NMR (CDCl₃): 5.50-5.80 (br s, 1H), 3.85-4.08 (br q, 2H), 3.63-3.83(br q, 2H), 3.32-3.51 (br s, 2H), 1.14-1.36 (br t, 6H)

In this example, polymerisation experiments are carried out at roomtemperature and 35° C. The results are summarised in table 9.

TABLE 9 Starting monomer with structural units of formula (I) wherein Ar= 3,4-dichloro-2,5thienylene, R₀ = —NR₁R₂ with R₁ = R₂ = C₂H₅ in THFPolymerisation Yield Mw (g/mol) PD temperature (%) (in DMF) (in DMF)Room temperature 64 10400 1.8 35° C. 76 18500 2.8

EXAMPLE 9

In an ninth example, the synthesis of naphthalene-1,4-diylbismethyleneN,N-diethyl dithiocarbamate with a formula according to formula (I)wherein Ar=1,4-naphthalene, R₀=—NR₁R₂, R₁=R₂=C₂H₅, followed by thepolymerisation to the soluble precursor polymer with a formula accordingto formula (II) wherein Ar=1,4-naphthalene, R₃=R₄=H, is illustrated.

The yield of the reaction is 89%; ¹H NMR (CDCl₃): 8.10, (q, 2H), 7.585(q, 2H), 7.51 (s, 2H), 4.94 (s, 4H), 4.05 (q, J=7.2 Hz, 4H), 3.66 (q,J=7.2 Hz, 4H), 1.29 (2t, J=7.2 Hz, 6H), 1.21 (2t, J=7.2 Hz, 6H); ¹³C NMR(CDCl₃): 195.10, 132.21, 131.96, 127.93, 126.40, 124.86, 49.41, 46.70,40.48, 12.42, 11.61; DIP MS (EI, m/e): 302 (M⁺−SC(S)NEt₂), 148(SC(S)NEt₂), 116 (C(S)NEt₂). The polymerisation reaction is analogous tothat described in example 1. Polymerisation experiments are carried outat room temperature and 35° C. The results are summarised in table 10.

TABLE 10 Starting monomer with structural units of formula (I) whereinAr = 1,4-naphtalene, R₀ = —NR₁R₂ with R₁ = R₂ = C₂H₅ in THFPolymerisation Yield Mw (g/mol) PD temperature (%) (in DMF) (in DMF)Room temperature 80 14600 1.5 35° C. 78 15900 1.7

It is to be understood that although preferred embodiments, specificconstructions and configurations, as well as materials, have beendiscussed herein for devices according to the present invention, variouschanges or modifications in form and detail may be made withoutdeparting from the scope and spirit of this invention.

1. A precursor polymer compound having a formula:

wherein Ar is an aromatic divalent group or a heteroaromatic divalentgroup, wherein R₀ is selected from the group consisting of an aminogroup of formula —NR₁R₂, an alkyl group, an aryl group, an alkylarylgroup, an arylalkyl group, a thioether group, an ester group and an acidcarboxylic group, and wherein each of R₁, R₂, R₃ and R₄ is independentlyselected from the group consisting of hydrogen, a C₁-C₂₀-alkyl group, acyclic C₃-C₂₀-alkyl group, an aryl group, an alkylaryl group, anarylalkyl group, and a heterocyclic group, or R₁ and R₂ are linkedtogether to form a cycle, and wherein n is an integer from 5 to
 2000. 2.The precursor polymer of claim 1, wherein R₀ is an amino group —NR₁R₂.3. The precursor polymer of claim 1, wherein R₀ is an amino group—NR₁R₂, and wherein R₁ and R₂ are independently selected from the groupconsisting of a C₁-C₂₀-alkyl group, a cyclic C₃-C₂₀-alkyl group, an arylgroup, an alkylaryl group, an arylalkyl group and a heterocyclic group.4. The precursor polymer of claim 1, wherein R₀ is an amino group NR₁R₂,and wherein R₁ and R₂ are independently selected from the groupconsisting of a methyl group, an ethyl group, a propyl group, a phenylgroup, and a benzyl group.
 5. The precursor polymer of claim 1, whereinR₀ is an amino group —NR₁R₂, and wherein R₁ and R₂ are each an ethylgroup.
 6. The precursor polymer of claim 1, wherein Ar is an aromaticdivalent group having from 4 to 20 carbon atoms, wherein Ar isunsubstituted or substituted with one or more substituents independentlyselected from the group consisting of C₁-C₂₀-alkyl, C₃-C₂₀-alkoxy,C₁-C₂₀-alkylsulfate, a phenyl group and a benzyl group, and wherein Arcomprises from 0 to 4 heteroatoms selected from the group consisting ofoxygen, sulfur, and nitrogen.
 7. The precursor polymer of claim 1,wherein Ar is a phenyl group.
 8. The precursor polymer of claim 1,wherein Ar is 1,4-phenylene.
 9. The precursor polymer of claim 1,wherein Ar is 2,5-thienylene.
 10. The precursor polymer of claim 1,wherein R₀ is a phenyl group.
 11. The precursor polymer of claim 1,wherein R₀ is a methyl group.
 12. The precursor polymer of claim 1,wherein R₃ and R₄ are each hydrogen.
 13. The precursor polymer of claim1, wherein Ar is selected from the group consisting of 1,4-phenylene;2,6-naphthalenediyl; 1,4-naphthalenediyl; 1,4-anthracenediyl;2,6-anthracenediyl; 9,10-anthracenediyl; 2,5-thienylene; 2,4-thienylene;2,3-thienylene; 2,5-furanediyl; 2,5-pyrrolediyl;1,3,4-oxadiazole-2,5-diyl; 1,3,4-thiadiazole-2,5-diyl;2,5-benzo[c]thienylene; thieno[3,2-b]thiophene-2,5-diyl;pyrrolo[3,2-b]pyrrole-2,5-diyl; pyrene-2,7-diyl;4,5,9,10-tetrahydropyrene-2,7-diyl; 4,4′-bi-phenylene;phenantrene-2,7-diyl; 9,10-dihydrophenantrene-2,7-diyl;dibenzofurane-2,7-diyl; and dibenzothiophene-2,7-diyl.
 14. The precursorpolymer of claim 1, having an average molecular weight of from 5000Daltons to 1000000 Daltons.
 15. The precursor polymer of claim 1, havinga polydispersity of from 1.5 to 5.5.
 16. The precursor polymer of claim1, having a polydispersity below
 2. 17. The precursor polymer of claim1, having a polydispersity of from 1.5 to 2.